Check if a number is a double or an int

Question

I am trying to beautify a program by displaying 1.2 if it is 1.2 and 1 if it is 1 problem is I have stored the numbers into the arraylist as doubles. How can I check if a Number

Answer 1

I am C# programmer so I tested this in .Net. This should work in Java too (other than the lines that use the Console class to display the output.

class Program
{
    static void Main(string[] args)
    {
        double[] values = { 1.0, 3.5, 123.4567, 10.0, 1.0000000003 };
        int num = 0;
        for (int i = 0; i < values.Length; i++ )
        {
            num = (int) values[i];
            // compare the difference against a very small number to handle 
            // issues due floating point processor
            if (Math.Abs(values[i] - (double) num) < 0.00000000001)
            {
                Console.WriteLine(num);
            }
            else // print as double
            {
                Console.WriteLine(values[i]);
            }
        }
        Console.Read();
    }
}